Sectionalizing switch



Sept. 7, 1954 Filed Oct. 10, 1951 WITNESSES: 427

A. W. EDWARDS SECTIONALIZING SWITCH Fig.l. I5

2 Sheets-Sheet l INVENTOR Andrew W.Edw0rds.

p 7, 1954 A. w. EDWARDS 2,688,672

SECTIONALIZING SWITCH Filed Oct. 10, 1951 2 Sheets-Sheet 2 Fig.2.

WITNESSES: INVENTOR Angrew W.EdwordZ J ATTORNE Patented Sept. 7, 1954SECTIONALIZING SWITCH Andrew W. Edwards, East McKeesport, Pa., as-

signor to Westinghouse Electric Corporation East Pittsburgh, Pa., acorporation of Pennsylvania Application October 10, 1951, Serial No.250,587

Claims. I

My invention relates generally to circuit interrupters, and it hasreference in particular to automatic line sectionalizing switches.

Line sectionalizing switches are used in conjunction with automaticreclosing circuit breakers for isolating faulted sections of the line inorder to maintain the maximum amount of service continuity. Theycomprise, in general, a switch mechanism which is controlled by a faultcounter which is arranged to open and lock open the switch mechanismafter a predetermined number of operations of an associated reclosingcircuit breaker, while such circuit breaker is open. To obtain the bestperformance, the fault counters must be arranged to reset to theirinitial position if the number of closely successive fault interruptionsby the reclosing breaker is not sufficient to cause opening and lockingopen of the switch mechanism. The fault counters must also beco-ordinated with the counting means of an associated reclosing circuitbreaker, so as to make it impossible to cause lockout of the circuitbreaker by repeated manual reclosing of the sectionalizing switch. Thus,it must be impossible for the fault counter of the sectionalizing switchto reset before that of the reclosing breaker. One way of accomplishingthis result is to make the reset time of the sectionalizing switchcounter greater than that of the longest resetting time of any reclosingbreaker with which the sectionalizing switch may be used. This calls forrelatively close manufacturing tolerances in counters of the dashpottype, which are difficult to obtain and are at the same time costly.

Accordingly, it is an object of my invention to provide in an automaticsectionalizing switch, novel means for delaying the reset of the faultcounter thereof.

Another object of my invention is to provide in an automaticsectionalizing switch having a fault counter, for preventing reset ofthe counter, only when the switch is open.

It is also an object of my invention to provide in an automaticsectionalizing switch for utilizing releasable restraining meansactuated by the switch operating mechanism for preventing reset of thefault counter while the switch contacts are open.

It is an important object of my invention to provide in an automaticsectionalizing switch using a fluid operated fault counter whichnormally resets during a predetermined time interval after operation,for preventing the reset interval from commencing until the switch isreclosed.

Yet another object of my invention is to provide in an automaticsectionalizing switch for supporting releasable restraining means on theoperating mechanism of the switch for preventing reset of the faultcounter thereof while the switch is open.

Another important object of my invention is to provide in an automaticsectionalizing switch for utilizing magnetic means actuated by theoperating mechanism of the switch for preventing reset of the faultcounter thereof until the switch is reclosed.

These and other objects of this invention will become more apparent uponconsideration of the following detailed description of preferredembodiments thereof, when considered in connection with the accompanyingdrawings, in which:

Figure l is a substantially central vertical section of a sectionalizingswitch embodying the invention in one of its forms, with the faultcounter shown only partly in section;

Fig, 2 is an enlarged side elevational view of a principal part of thecontact operating mechanism and the fault counter of a switch similar tothat of Fig. l, with the fault counter shown in section, butillustrating a different embodiment of the invention; and

Fig. 3 is a side elevational view of the operating mechanism and counterof Fig. 2 shown in the open position.

Referring to the drawings, it will be seen that an automaticsectionalizing switch or sectionalizer I1 is shown in Fig. l as beingenclosed within a metal tank 21, which is provided with an insulatingliner 28, and which is surmounted by a top casting 29. The form ofsectionalizer described herein may be substantially similar to thatdescribed in detail in the copending application Serial No. 189,082 ofJames M. Wallace, filed October 9, 1950, and entitled CircuitInterrupter and Counter Therefor, which application is assigned to theassignee of the present invention, and while this invention includescertain features of cooperation with this particular form ofsectionalizer, it is not limited thereto, because it will be apparentthat it may be embodied in sectionalizers which are of a specificallydifferent form. As described in the said Wallace application, anincoming line 15 enters through a bushing 3! which terminates inside ofthe tank. The circuit then continues, through a conductor 32 to asectionalizer coil 19. From the sectionalizer coil IS, the circuitcontinues through a conductor 33 which is insulated from conductor 32 byinsulation 35, back underneath the bushing 31 for the incoming lead [5,and thence to the terminal 34 which constitutes one of the stationarycontacts of the sectionalizer which are disposed to be engaged by amovable contact 26. Ordinarily, the sectionalizer has two bushings, eachwith its lead passing through the bushing, and each bushing terminates,at its bottom, in one of the stationary contacts of the sectionalizer,but since Fig. 1 shows an approximate central section through thesectionalizer, the second stationary contact is not visible. The movablecontact 28 is shown as a contact bar or bridge which presses up againstthe underside of the stationary contacts 3A and the other stationarycontact (not shown) in the closed position of the sectionalizer, andwhich is lowered by gravity, to operate the sectionalizer, upon therelease of a pull rod 36, which is shown in the form of an upwardlyextending insulating tube having guide links 25 pivotally connectedthereto and to a bracket 38 on the rod 36 intermediate the ends of thebar 20, by a pivot 39 and to a stationary pivot 4 l.

The sectionalizer I! can operate either in air, or in an insulating oil,or other insulating fluid. It is sometimes desirable for the counter 31to operate in oil, as it involves dashpot or fluid flow operation, assubsequently described, which is somewhat more difficult to obtain inair, with the necessary time constants. It is sometimes desirable tohave the contacts Sic-2B also operating in oil. Consequently, theapparatus is illustrated, by way of example, as having the counter 3'?and the contacts 3d2ll immersed in oil 459 which is contained in thetank 21.

A counter-and-lockout mechanism 23 is segregated, into its componentparts, consisting of the counter 31 and an operating-mechanism.

The operating mechanism com-prises a bellcrank trigger 53 disposed tosupport a roller 50 at one end of a lever A! which is pivotallysupported by a fixed pivot 48 on a U-shaped bracket 49 secured to thecasting 29, and carries a pivot 44 which comprises one of the terminalpoints of a lever 43. A toggle mechanism, including a lever 46 pivotallyconnected to the lever as by a pivot 45, and an operating-handle 60pivotally supported on the casting 29 by a pivot S I, comprises theother terminal point of support for the lever 43. The pull rod 36 isconnected to the lever l3 by a pivot 42. The trigger 53 has a downwardlyextending abutment portion 56 which is adapted to be tripped when anupward movement of a trip pin 51 of the counter 3'! raises said abutmentpoint 56 of the trigger, whereupon the linkage of the operatingmechanism permits the pull rod 36 and the movable contact member 20 todrop freely in the opening operation of the mechanism.

The counter 37 is suspended from the top of the top casting 29, by meansof a plurality of depending insulating supports or tubes ll], whichsupport a bottom plate H of the counter.

The counter proper 31 comprises, as show-n in Figs. 1 and 2, avertically disposed tube 72, which is preferably made of brass or othernon-magnetizable metal. The lower end of the tube is disposed to beclosed by a plug 13 of iron or other magnetic material, while the top ofthe tube 12 is open. The series current coil i9 surrounds a portion ofthe tube 1-2, intermediate between its upper and lower ends.-Immediately above the coil [9 is a perforated magnetizable plate 74which is secured to the bottom plate H by bolts 15. The plates areperforated so as to surround the tube 12. The plates Hand H serve as thetwo pole pieces of an electromagnetic circuit, the excitation of whichis provided by the coil I9.

Inside of the tube 12 is a magnetizable core or armature 16, which issliclably movable, with a close fit of say perhaps 3 mils radialclearance, within said tube. The armature 16 normally extends partlyabove and partly below the level of the upper plate 14, being located bymeans of a shoulder 69 in the tube, while the plug 73 is disposed partlyabove and partly below the lower plate H. Both the armature 16 and theplug 13 thus extend partly within and partly without the space betweenthe two plates is and l I.

In accordance with the description of the copending Wallace application,the armature 16 may comprise two relatively movable elements, namely, acore 11 of iron or other magnetic material having a cylindricalextension 18 at the upper end, and a movable cap or piston of anon-magnetic material such as brass, closely surrounding the extension.Snap rings of iron or other suitable magnetic materia1 may be disposedin spaced grooves on the piston 88 to provide projecting ribs which arevertically spaced from each other by a spacing which is preferablyapproximately the same distance as the closable distance between thecore I! and the plug 13 so that it will magnetically lock the piston inits different stepped positions against unwanted vertical displacementor slippage. A snap ring 88 of magnetic material may be disposed in agroove 81 about the tube '12 in line with the plate 14 to assist inconcentrating the magnetic flux between the plate and the rings 85. Acompression spring :19 is disposed between the core 11 and the plug 73,so that when the coil I9 is sufficiently energized, such as by a faultcurrent, the core 11 is drawn downwardly towards the plug, storing upenergy in the interposed compression spring 19, as will be more fullydescribed hereafter.

Both the core T7 and the plug 13 are provided with central bores 81, andthe lower end of each of these bores is provided with an orificeclosable by means of a ball check valve 82, so that the fluid which isentrapped within the closed lower end of the tube 12 resists any rapiddownward movement of the piston ac, because of the closing of the ballvalve 82 in the plug 13, while the valves permit the free upwardmovement of the piston '80 and core Tl. The entrapped fluid could be anygas or liquid having the required viscosity in comparison with themechanical clearances which are provided. The idea is to permit therespective core TI and piston 80 to move freely upwardly, in astep-by-step motion, as will be subsequently described, while permittingthem to drift back downwardly again, by fluid leakage, at a very slowrate.

At the top of the armature 15 'of the piston 80, is afifixed anupstanding pin 84, which extends upwardly to a point'above the open topend of the tube 12. This pin 84 is surrounded by a tubular tip or trippin 57, which is capable of serving as an adjustable vertical extensionof the pin 84. This vertical adjustment is effiected in any one of aplurality of vertical spaced positions corresponding to the spacingbetween the core 7'! and the plug 13, by means of a cottervpin 85, .sothat adjustment may be made for any desired number of counts, such as 1,2, 3 or 4, within the range of the counting-mechanism 31 In order toincrease the resetting time of the counter 3'! after the sectionalizingswitch has locked open, releasable means such as the belltiallyhorizontal arm 9| depending leg 92 crank spring 90 may be provided. Thespring 90 may comprise, as shown in Fig. 1, a substan having anangularly related leg 82 disposed to be engaged by the lower edge of thelever 43 when the switch opens. A may be connected to the arm 9| by aloop 93 disposed to be positioned about the roller 63 on the pivot 54 ofthe bellcrank lever 53. The leg 92 may be provided with a foot 95disposed to be inserted under the lower edge of the trip pin 51 when thearm 9| is engaged by the lever 43. This edge may be beveled as at 98 tofacilitate releasing the trip pin.

In the operation of the counting-mechanism 31, when the coil I9 is firstenergized with a current corresponding to the setting of the counter,the core 11 of the armature 18 is drawn downwardly toward the plug 13,so as to close the air gap which separates the inner ends of saidarmature and plug. The fluid between the core TI and plug 73 cannot movedownwardly because of the pressure of the fluid flow valve 82 in theplug 13, so the fluid between the armature and plug is forced upwardlythrough the check valve 82 in the core 71, and hence the piston 88remains in the position shown. The attractive force between the upperplate 14 and the upper magnetic ring 85 is enhanced by the magnetic snapring 88 on the tube 12, and the piston 88 is thus held securely inposition as the armature 18 moves downwardly.

When there is a fault on the distribution line, within the protectivereach of an automatic reclosing circuit breaker, the recloser contactthereof quickly opens, and quickly again recloses, but during the moment(12 cycles or more, in a 60-cycle line) when said recloser contact wasopen, the sectionalizer coil I8 is deenergized, reducing the attractiveforce between the armature 16 and plug 13. The compression spring 19between the core 11 and plug 13 expands, and pushes the core upwardagain, to the normal separation-distance. During this action, however,fluid in the armature 16 is entrapped and cannot move downwardly,because of the fluid flow valve 82 in the core 11, and hence the piston80 and the core 11 must move upwardly together, which they are free todo, so far as fluid-action is concerned, because the lower valve 82 inthe plug 13 will open during such movement. The

magnetic attraction between the upper plate 14 and the correspondingmagnetizable ring 85 of the piston 88 of the armature 16 is nowpractically non-existent, because of the deenergization of the coil [8,and hence the piston 80 of the armature 16 is notched upwardly by adistance corresponding to approximately the amount of compression of thespring 19. Upon re-energization of the coil l9 above the rated value,the magnetic attraction between the rings 85 and 86 serves to accuratelyposition the piston 88 and thus correct any undershoot or overshoot.

If a fault continues on the distribution system, at a point beyond thesectionalizer coil 19, the reclosure of the recloser contactre-energizes the sectionalizer coil l8 and causes a second compressionof the spring 19, in the manner already described. If the fault is stillon the system, as has just been assumed, the recloser-contact againopens, and a second upward stepping-movement of the trip pin 51 isobtained.' Thus the stepby-step movement of the counter mechanismcontinues. The ring 88 about the tube 12, being of a magnetic material,acts to concentrate the magnetic flux in the gap between the plate 14and example, a collar 97 of the rings 85, thus increasing the effectivelooking power thereof, and accurately positioning the piston each timeto prevent cumulative error.

When the last upward stepping of the piston of the armature I6 isobtained, depending upon the vertical positioning of the trip pin ortubular tip 51, this pin 5! comes into contact with the trigger 53during this last upward movement, and trips out the sectionalizercontact 28. It will be noted that this last upward movement of the trippin 51 occurs during a time when the current in the sectionalizer coil[9 is off. In the operation of the recloser, the current remains off,that is, the recloser contact remains open for a minimum of 12 cycles(on a Gil-cycle line), before the recloser contact recloses. The openingof the sectionalizer contact 20 requires something like two or threecycles, so that it is seen that the sectionalizer contact 20 opensduring the current off period, so that the sectionalizer contact 20 doesnot have to interrupt any substantial current.

As the contact rod 38 drops, lever 43 rotates counterclockwise until itstrikes roller 63, engaging arm 9! and rotating the springcounterclockwise. The foot of leg 92 is moved in under the lower edge ofthe trip pin 5! to prevent resetting of the counter. The counter mayonly reset sufliciently to permit bellcrank lever 53 to reset, so thatthe lever 41 is reset by being raised until roller 50 rests on the arm52 of the lever 53, thus readying the switch for reclosing.

When the switch is reclosed by raising the handle 60, the counter 31' isconditioned for an immediate trip, thus affording the maximumprotection, since the recloser counter will have at least partiallyreset and cannot, therefore, be locked out improperly by reason of theswitch resetting first.

Referring particularly to Figs. 2 and 3 of the invention, it will beseen that in this embodiment of the invention the operating mechanism isidentical with that of Fig. 1, but resetting of the counter 37 may beprevented by magnetic means, instead of the spring 98 of Fig. 1. Formagnetic material such as iron, steel, or the like, may be disposed onthe piston 80, being disposed about the pin 84 within the tube 12. Apermanent magnet 88 having spaced pole pieces 99 and H38 may be securedto the contact rod 38, as by a set screw lfll. The magnet 98 and collar9i may be so related that they are disposed opposite each other when thecontact rod has dropped to the full open position and the counter 31 hasjust reset sufficiently to permit the bellcrank lever 53 to reset andlatch the lever 46, as shown in Fig. 3. When the breaker is closed, asshown in Fig. 2, the magnet 98 has no influence on the collar 97 as theyare relatively remote from each other.

Accordingly, when the sectionalizer switch opens, its counter will inboth instances be prevented from resetting any further than is necessaryto permit reclosing the switch. Thus the reclosing circuit breakerassociated therewith can at least partially reset, and it will not besubject to lockout improperly as by the reclosing of the sectionalizingswitch before the recloser counter resets.

While I have illustrated my invention in but two exemplary forms ofembodiment, which are now preferred, it is to be understood that theinvention is susceptible of considerable modification, by way ofadditions, omissions and substitution of various equivalents, withoutdeparting from the essential spirit of my invention, particularly in itsbroader aspects. It is desired, therefore, that the appended claimsshall be accorded the broadest construction consistent with theirlanguage.

I claim as my invention:

1. In a circuit interrupter, separable contacts, releasable meansnormally operable to prevent separation of said contacts, counting meanshaving actuating means for actuating it from an initial position inresponse to a predetermined number of circuit interruptions to efiectoperaate said latch means to effect separation of said contacts onlyafter a predetermined number of such interruptions, said counting meansbeing disposed to slowly reset after an operation, an operatingmechanism including a movable member operable to reclose said contacts,and releasable means including a part operable in response to separationof the contacts to prevent return of the counting means to said initialposition, said part of the releasable means being operable to releasesaid counting means in response to operation of the movable member ofthe operating means to reclose said contacts.

3. A circuit interrupter comprising, separable contacts, latch meansnormally holding said contacts closed, means movable byelectroresponsive means operable from an initial position to effectoperation of the latch means to effect separation of said contacts onlyafter a plurality of interruptions of the circuit during an overload,operating means for one of the contacts including a lever operable toactuate said one contact to reclose said contacts and releasable meansactuated by said lever during separation of said contacts to engage andprevent return of said means movable by the electroresponsive means tosaid initial position, while the contacts are separated.

4. In a circuit interrupter, separable contact means, fluid-actuatedcounting means operable from an initial position to efiect separation.of said contact means only after a predetermined number of interruptionsor an overload, operating means connected with one of the contact meansfor reclosing said contact means, and having a part movable to aposition to exert a restraining force on the counting means to preventit from returning to the initial position, said part being movable tosaid position by said operating means when said contact means areseparated.

5. In a circuit interrupter, separable contacts, releasable latch meansnormally maintaining said contacts closed, counting means operable inresponse to a predetermined number of closely successive interruptionsto actuate said releasable latch means and effect separation of saidcon-.

tacts, operating means operatively connected with one of said contactsfor actuating said contact to effect reclosing of said contacts,normally ineffective means having a movable part operable in response tomovement of said operating means during separation of said contacts to aposition to exert a restraining force on the counting means and preventreset of said counting means, said movable part of said normallyinefiective means being moved to a different position in which it isrendered ineffective upon operation of said operating means to reclosesaid contacts.

6. A circuit interrupter comprising, separable contacts, an operatingmechanism supporting one of the contacts for separating and reclosingsaid contacts, releasable means engaging a part of said mechanism formaintaining said operating mechanism in a contact closed position, fluidpressure actuated counting means having a movable part selectivelyresponsive to a predetermined value of overcurrent and interruptionthereof to progressively advance in response to closely consecutiveinterruptions for operating the releasable means to release theoperating mechanism and separate the contacts only after a predeterminednumber of closely successive overcurrents and interruptions, andrestraining means having a part actuated by the operating mechanism to apredetermined position to prevent the counting means from resetting solong as the contacts are separated.

'1. A circuit interrupter comprising, separable contacts, an operatingmechanism including a movable member for actuating said contacts toseparate or reclose them, releasable means for maintaining said memberin a position with the contacts closed, counting means having a partoperable from an initial position to actuate and effect release of saidreleasable means in response to an overcurrent and a plurality ofclosely successive interruptions thereof, and a normally ineffectiveresilient restraining means actuated by the movable member of saidmechanism to engage said part of said counting means to prevent returnthereof to the initial position until said mechanism is operated toreclose said contacts.

8. A circuit interrupter comprising, separable contacts, an operatingmechanism for separating and reclosing said contacts, including acontact rod carrying one of the contacts and a lever pivotally connectedto said rod, a releasable support pivotally supporting said lever,counting means having an initial position to which it slowly returns,said counting means being operable progressively in response to closelysuccessive pulses of current above a predetermined value to advance fromsaid initial position to actuate and release said releasable support,and resilient restraining means actuated by said lever in response tomovement thereof upon release of said releasable support to engage andprevent return of said counting means to the initial position.

9. In a circuit interrupter, separable contacts, releasable meansnormally maintaining said contacts closed, counting means having a partprogressively advanced in response to closely successive interruptionsof an overload to actuate the releasable means and efiect separation ofthe contacts after a predetermined number of such interruptions, and aspring restraining member actuated to a predetermined position inresponse to separation of said contacts to engage and prevent more thana predetermined resetting of said progressively advanced part so long asthe contacts remain separated.

10. A circuit interrupter comprising, separable contacts, means normallmaintaining said contacts closed, fluid operated counting means having amovable part operable from an initial position in response to closelysuccessive interruptions of a current in excess of a predetermined valueto progressively advance and effect separation of said contacts, saidcounting means being biased to return to said initial position uponseparation of said contacts, and a normally inc fective resilientrestraining member actuated to a predetermined position by means movablein response to separation of said contacts to maintain the movable partof the counting means in a position intermediate its operating andinitial positions so long as the contacts are separated.

11. A circuit interrupter comprising, separable contacts, an operatingmechanism for separating and closing said contacts, releasable meansnormally maintaining the operating mechanism in a contact closedposition, counting means having a part progressively advanceable from aninitial position in response only to a predetermined number of closelysuccessive interruptions of an overcurrent in said circuit for actuatingsaid releasable means and effecting operation of said mechanism toseparate said contacts, and restraining means carried by the operatingmechanism for exerting a restraining force on said part for preventingreturn of the counting means to the initial position so long as thecontacts are separated.

12. A circuit interrupter comprising, separable contacts, an operatingmechanism connected to at least one of said contacts including a movablecontact rod, releasable means for maintaining the operating mechanism ina closed contact position, counting means having a movable partadvanceable from an initial position in response to a predeterminednumber of closely successive interruptions of an overcurrent to actuateand release said releasable means and effect movement of said contactrod to separate said contacts, and means carried by the contact rodmovable to a predetermined position in response to said movement of therod for preventing the counting means from returning to said initialposition While the contacts are separated.

13. A circuit interrupter comprising, separable contacts, an operatingmechanism for effecting separation and reclosing of said contacts, latchmeans normally maintaining said mechanism in a closed contact position,counting means having a movable part progressively advanceable from aninitial position in response to a predetermined number of closelysuccessive interruptions of an overcurrent to actuate the latch meansfor permitting operation of the mechanism to separate said contacts, andmagnetic means including a part actuated by the operating mechanism forpreventing return of the counting means to the initial position for apredetermined time after said contacts are reclosed.

14. A circuit interrupter comprising, separable contacts, an operatingmechanism for effecting separation and reclosing of said contacts, fluidactuated counting means having a movable part advanceable progressivelyfrom an initial position in response to a predetermined number ofclosely successive interruptions of an overload current for actuating apart of the mechanism and effecting operation of the mechanism toseparate said contacts, and means including a movable part actuated inresponse to operation of said mechanism to separate said contacts toexert a restraining force on the counting means for preventing return ofsaid counting means to the initial position until a predetermined timeafter the mechanism is operated to reclose said contacts.

15. A circuit interrupter comprising, separable contacts, an operatingmechanism for said con tacts including a movable contact rod operativelyconnected with one of the contacts, a latch normally maintaining the rodin a closed contact position, counting means having a part movable froman initial position in response to a predetermined number of operationsof the mechanism to actuate the latch and permit movement of the contactrod to separate the contacts, magnetic means on the movable part of thecounting means, and magnetic means carried by the contact rod movable toa position in which it is cooperative with the magnetic means on themovable part of the counting means when the contacts are separated toprevent the counting means from returning to the initial position.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,337,713 Garlington Dec. 28, 1943 2,442,477 Wallace et a1June 1, 1948 2,452,233 Gerard et a1 Oct. 26, 1948 2,477,067 Kyle, Jr. eta1. July 26, 1949 2,524,525 Hermann et a1. Oct. 3, 1950

